Using a birth‐and‐death process to estimate the steady‐state distribution of a periodic queue

If the number of customers in a queueing system as a function of time has a proper limiting steady‐state distribution, then that steady‐state distribution can be estimated from system data by fitting a general stationary birth‐and‐death (BD) process model to the data and solving for its steady‐state distribution using the familiar local‐balance steady‐state equation for BD processes, even if the actual process is not a BD process. We show that this indirect way to estimate the steady‐state distribution can be effective for periodic queues, because the fitted birth and death rates often have special structure allowing them to be estimated efficiently by fitting parametric functions with only a few parameters, for example, 2. We focus on the multiserver M_t/GI/s queue with a nonhomogeneous Poisson arrival process having a periodic time‐varying rate function. We establish properties of its steady‐state distribution and fitted BD rates. We also show that the fitted BD rates can be a useful diagnostic tool to see if an M_t/GI/s model is appropriate for a complex queueing system. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 664–685, 2015     

ON RATIONAL CHOICE THEORY AND THE STUDY OF TERRORISM

When rational choice theory is applied to the study of terrorism, it is important that attention be given to the derived principles of constrained utility maximization. Particularly useful is the Slutsky equation, which rigorously analyzes the quantity response in one activity to a price change in another. By directing attention to assumptions and/or information about compensated cross price elasticities, expenditure shares, and income elasticities, the Slutsky equation can provide critical guidance in both theoretical and empirical analysis.     

The impact of defense and non‐defense public spending on growth in Asia and Latin America∗

For a three‐sector Feder‐Ram framework, we present time‐series, cross‐sectional estimates for two cohorts, consisting of Asian and Latin American countries. The estimates indicate that private investment, and defense and non‐defense public spending are growth promoting for alternative error components representations. For the best error components representation, greater growth enhancement is associated with the two forms of public spending in Asia than in Latin America, while the opposite comparison characterizes private investment. Although defense is growth promoting, an opportunity cost exists insofar as non‐defense spending, financed by defense spending, appears to give a small net boost to growth in Latin America.     

Optimal defence structure for a small country

Small countries may not be able to afford all force elements (army, navy, air-force) operated by larger countries and certainly cannot afford all sub-elements (aircraft carriers, submarines, etc). This paper provides a framework for a small country to analyse its force structure, examining the influence of objectives, international co-operation, funding and technological constraints, and uncertainty. We analyse when a small country may choose to retain a balanced structure (with each force element) and when it may choose to drop one or more elements. The issues are illustrated with the decision by the New Zealand government over whether to retain a strike aircraft capacity.     

Military Expenditure,Endogeneity and Economic Growth

Abstract

While not always a concern for the general economic growth literature, the debate over the effects of military spending on growth continues to develop, with no consensus, but a deepening understanding of the limitations of previous work. One important issue that has not been adequately dealt with is the endogeneity of military spending in the growth equation, mainly because of the difficulty of finding any variables that would make adequate instruments. This paper considers this issue, using an endogenous growth model estimated on a large sample of 109 non-high-income countries for the period 1998–2012. The empirical analysis is framed within an instrumental variable setting that exploits the increase in military spending that occurs when unrest in a country escalates to turmoil. The estimation results show that endogeneity arising from reverse causality is a crucial issue, with the instrumental variable estimates providing a larger significant negative effect of military spending on growth than OLS would. This result is found to be robust to different sources of heterogeneity and different time periods.     

WHEN THE COLD WAR WAS HOT

15 Minutes: General Curtis LeMay and the Countdown to Nuclear Annihilation, by L. Douglas Keeney. St. Martin's Press, 2011. 384 pages, $27.     

U.S. policy on preventive war and preemption

In the aftermath of September 11, 2001 and Hurricane Katrina, the United States government has spent tens of billions of dollars to improve the nation's ability to respond to a natural disaster or terrorist attack, but the emphasis on immediate first response has left many long-term environmental, political, and technological challenges unaddressed. Although a dirty bomb attack is unlikely to yield the same amount of physical devastation and death as caused by Katrina or a nuclear weapon, the social, psychological, and economic impact would be enormous. At present, however, the United States lacks the technology necessary to decontaminate a large, densely populated urban area under time, political, and economic constraints. This article reviews past cleanup experiences and current decontamination capabilities to consider the long-term implications of a dirty bomb, identifies weaknesses in America's existing response capabilities, notes possible areas of political friction, and considers the implications of the failure to adequately prepare. Having the appropriate decontamination techniques established and long-term plans in place before an incident occurs will significantly improve the government's ability to protect public and environmental security, establish a viable decontamination strategy, allow residents to return to their homes, and get the local economy back on its feet.